The present invention relates to a laser beam focus and alignment method and apparatus and especially to a focus and alignment method for focusing an engraving laser or the like.
In recent years, focus laser beam devices for use in welding, cutting, soldering, scribing, and engraving have come into wide use. These systems employ a laser mounted for control and focusing of the beam onto a workpiece. An optical system is used collimating and focusing the laser beam from an output lens directly onto the workpiece. For best efficiency, these laser systems require that the laser beam be aligned with the product that is to be engraved, welded, cut, soldered, or scribed and focused at a predetermined point. The laser beam can then be directed to engrave indicia, logos, or the like directly onto a workpiece. In a general purpose laser engraving system, the workpieces can be a wide variety of sizes and shapes which can be quickly attached to the apparatus directly in line with the output laser beam. Since the workpieces are of different shapes, it is necessary to align the laser beam for each particular workpiece so that the piece can be properly engraved with the laser beam. The same applies to the focusing of the laser beam used for welding, cutting, soldering, and scribing. Once the laser beam is focused and aligned for a particular workpiece, all of the workpieces of the same configuration can be engraved without readjusting the focus and alignment. However, in focused light engraving, individual units or small numbers of workpieces are engraved for individuals and small companies so that it becomes time consuming to refocus and realign the laser beam for each different workpiece or small number of workpieces.
The present invention is directed towards a laser beam focus and alignment method and apparatus for focusing an engraving laser or the like and can be rapidly attached to a focus engraving laser to quickly determine the focus and alignment for a particular workpiece. The focusing attachment is quickly attached onto the focus laser engraver over the output lens directly in line with the output for the laser where the focus and alignment can be rapidly accomplished and the attachment quickly removed for engraving the workpiece.
In the past, a variety of alignment or focusing systems have been used with laser beam devices. These include using LEDs placed adjacent the output of the laser device to shine one or more LED beams at the point of alignment or at the point of focus, which is moved with the output of the laser beam. Other systems for adjusting focused alignment or distance can be seen in the U.S. patent to Straus; U.S. Pat. No 1,750,370, for a camera strap for measuring distance from the camera lens, and in the Paullin patent, U.S. Pat. No. 4,608,573, for a focal point positioning tool for measuring the focal point on a conversion reflector. In the U.S. patent to Keppler et al., U.S. Pat. No 2,705,840, a height measuring device is provided which raises and lowers a head plate until it touches the head of a person. In the Dudley patent U.S. Pat. No. 4,888,881, a direct height measuring device for surveying instruments above the ground point uses an adaptor positioned in an instrument support on a tripod and a measuring tape is secured to measure the distance to ground. In the Emus, Jr. patent, U.S. Pat. No. 5,113,595, a dart board positioning device uses two measuring lines connected at right angles. The Kuehn patent, U.S. Pat. No. 1,280,045, shows a focal tester for eye lens while the Naiki patent, U.S. Pat. No. 5,113,291, is for an optical axis and focal adjustment mechanism for a semi-conductor laser and collimator lens. The Fidler et al. patent U.S. Pat. No. 5,289,220, is a detachable close-up lens assembly for an adjustable focus lens camera incorporating a photoranging system and uses a pair of focus ranging light beams for determining focus and distance.
The present invention is directed towards a laser beam focus and alignment method and apparatus for a focused engraving laser or the like which can be rapidly positioned for quickly determining the focus and alignment of a workpiece to be engraved, etched, cut, or the like and in which a focus and alignment attachment can be quickly removed from the output of the focused laser apparatus so that the workpiece can be engraved and which reduces the setup time for a focused engraving laser. The aim of the invention is to be able to rapidly focus and align a focused engraving laser or other focused laser system to reduce the time required for engraving, scribing, welding, cutting, soldering a workpiece.